Governor for elevators.



D. L LINDQUIST. GOVERNOR FOR ELEVATORS. APPLICATION mso ocr. 211. i913.

Patented Mar. 25, 1919.

WITNESSES:

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UNITED STATES PATENT OFFICE.

DAVID L. LINDQUIST, OF YONKERS, NEW YORK, ASSIGNOR T0 OTIS ELEVATOR COM- PANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

GOVERNOR FOR ELEVATORS.

Specification of Letters Patent.

Patented Mar. 25, 1919.

Application filed October 28, 1913. Serial No. 797,712.

To all whom it may concern:

Be it known that I, DAVID L. LIND UIs'r, a subject of the King of Sweden, residing in Yonkers, in the county of Vestchester and State of New York, have invented a new and useful Improvement in Governors for Elevators, of which the following is a specification.

My invention relates to safety devices for elevators and is particularly directed to the governor used for actuating an elevator safety device in the event of excessive speed.

An object of the invention is the provision of a. simple, practical and eflicient governor which will infallib-ly operate exactly at the speed for which it is set.

Another object of the invention is the provision of a governor which will reset itself automatically.

A further object of the invention is the provision of a governor which is responsive to the action of centrifugal force and inertia.

Another object of the invention is the provision of a governor whose operative functions are unimpaired by disuse or neglect.

Other objects of the invention will appear hereinafter, the novel combinations of elements being pointed out in the appended claims.

Figure 1 of the drawings represents an elevation view in part section of a governor containing an embodiment of my invention; Fig. 2 is a side elevation view of the governor; Fig. 3 is a diagrammatic view of an elevator showing the application of the in vention thereto; Figs. 4 and 5 are diagrammatic views illustrating the principle of operation.

Like reference characters denote similar parts in all of the figures.

For obvious reasons, it is of the utmost importance that the safety device of an elevator shall 'be infallible in operation. While the safety device in itself may be all that could be desired as far as its operation is con cerned, the means for actuating the safety device, which is universally some form of centrifugal governor, is often found in actual practice to be unreliable and uncertain in action and cannot always be depended upon to act "at a predetermined speed of the elevator car.

The reasons for this may be pointed out as follows: It is customary to locate the governor of an elevator safety device at the top of the hatohway where it is troublesome to get at and sometimes quite inaccessible and hence in all likelihood it seldom if ever receives the care and attention it should have in order to keep it in proper working condition. Then again dust and dirt are bound to collect on the working parts of the governor, and, mixing with the lubricating oil, will form a gummy substance which in time hardens to such an extent that the governor may refuse to act when it should. Furthermore it often happens that the elevator is out of use for one reason or another, often for a considerable period of time, and the governor being at rest at such time, the governor parts may rust together or develop friction therein. Even though the governor should act under these unfavorable conditions, its sensitiveness will be seriously impaired and it will only operate at a speed far in excess of that for which it was set. V

A governor embodying-my invention will invariably operate at the speed for which it is set or adjusted, regardless of disuse or neglect or other unfavorable conditions.

Referring to Figs. 1 and 2 of the drawings,-the governor Gr comprises a sheave 1 having a peripheral groove in which lies the governor cable 2. This sheave 1 is free to rotate upon a shaft 3 which is carried by a bifurcated bracket 1 and secured therein against turning. At diametrically opposite points on the sheave 1, weighted members, such as 5 and 6, are pivoted upon pins 7 and 8, respectively, and these members are tied together by a pair of links 9 and 10 which insure their simultaneous movement. The weighted member 5 carries a roller 11 which rolls upon the surface of a cam 12 adjustably secured on the shaft 3, and locked against rotary movement by means of a set screw 14'. This cam is substantially circular in form, and is provided with a portion 13 which may be raised, or may be a depression in the cam surface. The weighted members 5 and 6 are normally .in retracted position, as shown, and are maintained in such position by means of springs acting on the links 9 and 10. Each of the links, such as 10, has a projection 14, to which is secured a pin 15. The latter slides in a sleeve 16, one end of which is thrust against one of the spokes of the sheave 1 by means of a spring 17, whose tension may be varied to any desired amount by means of washers 18. A bifurcated arm 19 is pivoted upon the bracket a by a pin 20 located below the shaft, 3 and this arm is normally maintained in contact with a stop 21 by reason of its own weight. At the upper end of the arm 19 a rectangular open ing 22 is provided which forms a housing for a stiff coil compression spring Coacting with the spring is a cable gripping or wedging member which may slide in a slot 26 and which is carried upon one end of a rod 27. A. shoulder is provided in the rod 27, and is adapted to engage and raise the collar 24, and thereby further compress the spring 23 upon the operation of the governor. The wedge member 25 is arranged in alinement with the groove in the cable sheave 1 and normally occupies a position a short distance removed from the governor cable 2, which distance may be varied to suit cables of different diameters by setting up on the nuts 29 and thus raising the member 25. Each of the arms of the bifurcated member 19 is provided with a trip 30 which is removed a slight distance from the path of rotation of the weighted members 5 and 6.

In F ig. 3 I show the application of my governor to an elevator safety device. In this figure C represents an elevator car which is raised and lowered by a hydraulic, electric or other motor, and which carries a safety dew'ce S of any of the prevailing types. The governor cable 2 is normally connected to the car by means of a releasing carrier 8 11, and passes up over the sheave 1 of the governor G and about a tension de' vice T located at the bottom of the hatchway. A safety cable 31 is affixed to the governor cable 2, and is in the present in stance wrapped about a drum 32, the turning of which effects the operation of the safety device in the usual way. A hand operated device 33 in the car is connected to the drum 32 and provides a convenient means for enabling the car operator to actuate the safety device at any time. The governor cable 2 normally runs with the car, by virtue of the yielding connection therebetween afforded by the releasing carrier 34. Should the car reach a speed in excess of that for which the governor is set, the lat ter restrains the governor cable by clamping the, same and the continued movement of the car disconnects the former cable from the car and effects the rotation of the safety drum 32 to apply the usual gripping jaws to the elevator guide rails or the safety cable 31 may be connected to actuate any of the ordinary types of safety devices such as those employing wedges, clamps, retarders, etc, the particular type of safety device which may be actuated by the governor being immaterial.

Under conditions of normal car speed, the operation of the governor as arranged in Figs. 1 and 2, is as follows. As the elevator moves downwardly, the sheave 1 and connected weighted members 5 and 6, will be rotated in a. clockwise direction. At each revolution of the governor sheave, the roller 11 on the weighted member 5 rides over the raised portion 13 on the cam 12, and in so doing, the weighted member 5, together with the connected weighted member 6 are rocked upon their pivots 7 and 8, respectively. The weighted ends of these members are thus moved outwardly into a position to engage the trips 30 formed in the arm 19. Before such engagement takes place, however, the roller 11 rides over the projection on the cam, and the springs 17 17, pull the weight ed arms inwardly so that the roller does not leave the )eriphery of the cam and the members 5 and 6 pass by the trips 30 without engaging the same. From this it will be seen that at each revolution of the governor sheave the weigh-ted arms will positively be moved into engaging or tripping position only to be pulled back out of engaging position. Thus the working parts of the governor are continually kept in a. state of motion while the elevator is being operated, which insures that the governor will always be in condition to act when the time comes, and also insures against the possibility of sticking of the parts due to dust, hardened oil, rust or other causes, incident to disuse or neglect.

In case of excessive car speed the too rapid rotation of the sheave 1 causes the weighted members 5 and 6 to fly outwardly and engage the trips 30. The continued rotation of the sheave swings the arm 19 about its pivot 20 in a right hand direction, and owing to the eccentricity of this pivot with respect to the center of rotation of the sheave, i. 6-, the shaft 3, the wedge member 25 is carried into frictional engagement with the governor cable 2, and-the latter isj ammed between the sheave and the wedge 25 with a predetermined pressure which may be regulated by adjusting the tension of the spring 23. As the arm 19 is moved the part 35 thereon engages the rim of the sheave and acts as a wedging brake to prevent its further rotation. In reversing the elevator after the safety device has operated, the governor will be rotated in an anti-clockwise-direction and thereby reset itself.

The operation of the governor may be said to be effected by the action of centrifugal force and that of inertia, either one of which acting alone will effect the desired result. For instance, the action of centrifugal force alone on the weighted members 5 and 6 will cause them to move outwardly against the action of the springs 17, 17, to trip the governor when the speed b comes excessive. The action ofinertiaalone on the weighted members tends to prevent the rollers from following the surface of the cam throughout its entire periphery when the speed of the sheave is excessive. For example, assume that the speed of the governor is not in excess of its normal speed. As a roller moves over the cam surface and reaches the projection 13, the weighted members will have assumed their normal outward extent of movement into position to engage the trips 30, 30. As the sheave continues to rotate, the roller is carried away from the high part of the cam and is immediately moved inwardly by the pull of the springs 17 so as to remain in contact with the cam periphery, and thereby pass by the trips 30, 30. This operation is repeated every time a roller engages the projection 13 on the cam. If, however, thespeed of the governor becomes excessive, the roller in passing the high part of the cam will not, as before, he maintained in contact with the cam, but will be carried .along a certain angular distance before the springs have had suiiicient time to overcome the inertia of the weighted members, this inertia tending to retard the action of the springs and prevent the almost instantaneous inward movement of the weighted members which movement is necessary to keep the roller and cam in contact when the speed is above normal. Since, therefore, the weighted members under excessive speed are not immediately pulled inwardly, the continued rotation of the sheave carries a member into engagement with the trips 30, 30, to effectthe actuation of the governor. From this it 1s seen that the governor will operate under the influence of centrifugal force acting alone, or under the influence of inertia acting alone, and furthermore, the operation of the governor may be due to their combined action.

In Fig. 4 the cam projection 13 is shown exaggerated for the purpose of better illustrating the operation. In this figure, the Weighted centrifugal member 5 1s represented by a square, while the trip 30 engaged thereby is represented by a rectangular figure. When the car is operating at normal speed,'in a downward direction, the axis of the roller 11 describes a path represented by the broken line a which takes'a form similar to the outline or periphery of the cam 12 and does not intersect the trip 30. If the car exceeds a predetermined speed, the roller 5 leaves the cam surface under the influence of centrifugal force and inertia at the high point thereon and the member 5 describes a curve substantially like that represented by the broken line b. In the first instance the member 5 does not engage the trip 30, whereas in the second instance corresponding to excessive speed, the path of the memher '5 represented by the line b intersects the trip 30 and an engagement therebetween takes place and the governor is operated. v

In Fig. 5 the cam 12 is of different form than the cam 12 of Fig. 4, in that it contains a recess 13. The broken lines a and 6 represent substantially the path of the member 5 for normal and excessive speeds respectively, and the illustration shows that the operation with a recessed cam is to all intents and purposes similar to that of a cam having a projection thereon. Whatever the shape of the cam may be, it is advisable not to make the cam too abrupt otherwise its action will tend to be noisy.

If the position of the cam be changed, or its contour altered, so that the high part or projection on the cam occupies a position of say 180 from that shown, the action of the governor will depend on centrifugal force alone, and the function of the cam will be merely to keep the governor parts in motion to prevent sticking The efiect of inertia may be controlled very readily by regulating the size of the cam projection or by varying the position of the cam upon the shaft 11. For instance, the farther the cam is moved in an anti-clockwise direction in Fig. 1, the higher the tripping speed will be, for the reason that the springs 17 17, will have more time to act and will pull the roller 11 back on the cam and thereby allow the weighted members 5 and 6 to pass beneath the trips 30, 30, and not engage the same.

Although the rocking motion which the weights are forced to assume will normally prevent sticking of the weights, it is still conceivable that through excessive neglect sticking will occur. The advantage of the arrangement lies in the fact, that. if this remote possibility should occur, the safety will trip. Evidently the weights can only stick when they are farthest removed from the center of the sheave and when they are therefore in an engaging position with refrence to the rope trip. The above occurrence will therefore trip the safety so that the governor will automatically indicate when it is not in proper condition to perform its functions.

From the foregoing description it will readily be seen that a governor containing an embodiment of my invention will act invariably at the exact speed for which it is set or adjusted even under the most unfavorable conditions met in practice. Since I make use of two means which may, and preferably do, act in conjunction to effect the tripping of the governor, the latter will be absolutely reliable and certain in action. The feature of having the governor parts in substantially constant motion insures against sticking or excessive friction from any cause whatsoever, and consequently the governor is always maintained in good operative condition. The governor is simple in form, and comprises but few parts, all of which are of generous dimensions and of more than sufficient strength to withstand the roughest kind of treatment.

While I have shown a preferred embodiment of my invention adapted particularly to the safety device of an elevator, the same may be used in many other connections wherein it is desired that a moving member such as a running rope or cable be restrained or retarded under certain conditionsof speed. Furthermore, the governor herein disclosed is designed to actuate an elevator safety device when the car is descending, but by a slight change in the arrangement of parts, which could readily be done by any mechanic, the governor can be made double acting so as to operate in both directions, the principle of operation remaining unchanged.

What I claim and desire to secure by Letters Patent of the United States is 1. A speed governor comprising a pivoted Weight arranged to be actuated by centrifin gal force, and additional means acting positively to assist centrifugal force to actuate the weight.

2. In a safety device for elevators, a governor comprising sheave a weight ranged to be actuated by centrifugal force, and a cam engaging the weight for actuating the same.

3. The combination, of a safety device, an elevator car, a centrifugal governor driven in synchronism with the car and arranged to operate the safety device, and means acting positively and independently of the action of centrifugal force on the governor for automatically effecting the preactuation of the governor.

4. The combination with an elevator safety device, of a governor for operating said safety device, comprising a sheave, a weight pivoted thereto, and means acting positively and independently of speed conditions for automatically rocking said weight on its pivot to prevent sticking thereof.

5. In a governor for operating the safety device of an elevator, the combination of a running cable, a governor sheave driven by said cable, a brake adapted to brake both the sheave and cable jointly and independently of eachother, a pivoted member supporting the said brake,*and'speedcontrolled means torocksaidmemberon'thepivot. Y I

6. In a'governor'for operating the safety device ofan elevator, the combination of 'a 'Gopiesof this patent may be obtained for running cable, a governor sheave driven by said cable, speed controlled means for applying a brake action to the said sheave and a yielding braking action to the cable.

7. A governor comprising a rotary sheave, a weighted member rotated 'by'the sheave adapted to lock the latter against movement upon excessive speed, and means independent of speed conditions for effecting a relative movement between the sheave and weight to prevent sticking of the said weight.

8. Ina safety device for elevators, a governor having in combination, a sheave, centrifugal connected members pivoted to the sheave, a self releasing locking device coacting with said sheave and centrifugal mem bers, and means independent of centrifugal action for maintaining said members in motion relative to that of the sheave and thereby prevent them from sticking.

9. In a safety device for elevators, a governor having in combination, a sheave, centrifugal connected members pivoted to the sheave, a self releasing locking device coacting with said sheave and centrifugal members, and a stationary camfor maintaining said members in constant intermittent motion relative to the sheave and thereby prevent sticking of the said members.

10. In a governor for operating a safety device of an elevator, the combination of a running cable, a governor sheave driven by said cable, a brake for the sheave, and a brake for the cable, and speed controlling means for operating said brakes, said brakes having movement relativeto each other.

11. In a governor for operating a safety device of an elevator, the combination of a runnin cable, a governor sheave driven by said mile, a brake for the sheave, a brake for thecable, a flexible connection between the two brakes, a speed controlling means for operating said brakes. 12. In a governor for operating a safety device, the combination of a running cable, a governor sheave driven by said cable, a brake for the sheave, a brake for the cable, means for controlling the extent of the brake action on the said cable, comprising a spring, a speed control means for operating said brakes.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

I DAVID L. LINDQUIST.

Witnesses:

a WALTER CrST-RANG,

. JAMES five cents each, by addressing the Commissioner; of Patents, Washington, D. (1. 

